It has always been a requirement to improve the gear-shifting comfort with respect to automatic transmissions. More specifically, it has been a requirement to reduce the jolts occurring during gear shifting. For example, U.S. patent application Ser. No. 08/050,085, filed Apr. 28, 1993, discloses a method for controlling the transmission wherein an output torque desired value is computed with this desired value being adjusted during gear shifting by an electronic motor power control.
Furthermore, the publication entitled "Bosch Technische Berichte", volume 7, book 4, (1983) pages 160 to 187, discloses various methods for controlling the transmission wherein the modulation pressure is controlled in a specific manner to increase the comfort of gear shifting and, additionally, an intervention on the motor for controlling the motor torque is carried out. The control values for the clutch torques or the pressure for the clutches in the transmission as well as for the intervention on the motor are usually stored in a characteristic field with such characteristic values being assigned to each gear shifting operation in dependence upon the particular rpm. In order to obtain these characteristic values, complex measurements are necessary during the adjustment phase in a motor vehicle provided with such a transmission.
A technician must vary the parameters influencing gear-shifting comfort when carrying out gear-shifting operations until optimal, relationships are present for each gear-shifting operation at each rpm or speed value. The configuration of a characteristic field of this kind is therefore complex and expensive. Even when optimal relationships are present in the test motor vehicle, significant differences in gear-shifting comfort for individual production motor vehicles occur because of variations in individual ones of the clutches, pressure controllers, valves and the like because, for obvious reasons, it is not possible to perform an adjustment of this kind for each individual motor vehicle. Furthermore, the gear-shifting comfort is affected by deterioration and, for motor vehicles having longer service times, by wear of the clutches, valve wear, seal wear and the like so that a reduction in comfort must be accepted since the transmission cannot be opened frequently for reasons of cost.